Module 1: Testing the ability of soil to hold water (field capacity). Science Voyages Link.
Module 2: Testing for fertilizer run-off. Science Voyages Link
Module 3: Comparing the growth of plants grown in medium enriched with fertilizer to
plants grown in regular soil. Science Voyages Link
Module 4: Identifying the effects of nutrient run-off on microscopic aquatic plant and
animal life. Science Voyages Link
Background: Lakes, streams, and oceans are all affected by run-off. Run-off can include fertilizers and pesticides from the lawn, garden, or farm. Run-off can also include animal wastes from large scale animal, and aquaculture farms. Run-off can lead to rapid growth of algae in small bodies of water due to the increased concentration of nutrients and to fish kills. This rapid growth of algae is called algae bloom. The effect on the water is called eutrification. Excessive nitrates in drinking water have also been linked to cancer. For these reasons it is important to develop a basic understanding of what run-off is, how it effects the environment, and how to prevent or reduce it. Further, it is also important to understand the reasons for using chemical fertilizers despite the inherent environmental dangers, and to try to learn of alternative sources of nitrogen for fertilizing plants. Factors that can affect the amount of run-off include the amount of fertilizer or animal waste on the surface of the ground before a rain, and the water field capacity of the soil. In order to understand the purpose of using fertilizers compare the growth of plants grown using commercial fertilizers with plants grown without any fertilizer. These three labs will be presented as separate modules. The modules can be used individually or together in whatever order is most interesting to you.
Text book correlations for Glencoe Science Voyages:
Level Blue, 8th grade: Unit 6, Chapters 17, 18, 19.
Level Green, 7th grade: Chapters 1, 8, and 14.
Level Red, 6th grade: Chapters 1, 2, 3, 4, 11.3, 16, 19, 20